1. Field of the Invention
The present invention is in the field of sound devices including speakers and pertains particularly to those devices used in such as hearing aid devices.
2. Discussion of the State of the Art
The modern art of hearing aid construction has been based upon the standard use of a balanced armature in the speaker component of the hearing aid for the past 50 years. A balanced armature is typically a metal strip aligned between poles of a cylindrical magnet. The armature is attached to a diaphragm in state-of-art hearing aid speakers. Vibration of the armature caused by magnetic field manipulation via current variations in the coil from an audio source or via microphone output current is transferred to a diaphragm to produce the amplified sound that the user hears.
Typical hearing aids take several different designs and general form factors including a “behind-the-ear” (BTE) form factor worn behind the ear whereby the sound vibrations are carried into the ear to an ear mold through a plastic tube. Another form is an “in-the-ear” or (ITE) form factor. Another form factor is “in-the-canal” (ITC) and still another form factor is “completely in the canal” (CIC). The smaller designs are generally less powerful and have fewer features than do the larger devices like the BTE design.
Likewise, there are other technologies used in state-of-art hearing aid systems for noise dampening and noise cancellation. Some of these involve digital signal processing, while others are more of a mechanical nature like using a ferrofluid to dampen the motion of the armature is an armature-based speaker device for a hearing aid. One problem with current devices is that the armature is extremely fragile and may be damaged or knocked out of proper alignment.
Therefore, what is clearly needed is a speaker device for a hearing aid that eliminates the need for a fragile armature and that provides better vibration with more dampening using a less complex architecture.